[PATCH] ARC: mm: fix leakage of memory allocated for PTE

[Pavel Kozlov]

> Good catch. Curious how did you find it. KMEMCHECK or some such or just oom.

I've run glibc tests with 5.16 kernel and got many oom-killer messages and even kernel 
panic because lack of memory. These symptoms pointed to an issue. kmemleak didn't 
show anything. Didn't try kmemcheck. I prepared a small test and used git bisect to find
to the "blame" commit.

>> Cc: <stable at vger.kernel.org> # 4.15.x

> You meant 5.15.x

Yes, you right, that's my typo.

> Added to for-curr.

Thanks!

Regards,
Pavel